Ask the Architect

On building a sunroom


Q. We’re thinking about putting a sunroom addition on our family room at the back of the house, and wonder if you have any pointers about them. Because they’re mostly glass, we’re wondering if tinted glass really keeps them from getting too warm, and also which is the best way to heat them in winter? We really love the daylight, and have looked at a few brochures. They’re more expensive than just a room, so we want to know your take on this.

A. Sunrooms, conservatories, greenhouses — whatever the term for them, they were originally conceived to create indoor gardens or for propagating plants, which is what I’d suggest having a glass sunroom for. They’re great for growing year-round gardens. But just like hot tubs and swimming pools, they’re a nice novelty that has a certain life span of enthusiastic use, followed by guilt that you don’t use it enough, followed by abandonment and eventual replacement after the frustration of trying to repair and seal them when they begin to leak.

During the 1990s, I incorporated sunroom additions on Long Island with a nationally known greenhouse company, and every one of the 400-plus clients I worked with told me that the pre-engineered systems, installed by factory-trained craftsmen, leaked. Though I wasn’t responsible for the systems, it was frustrating that my clients would contact me to help them by being their liaison. I finally had to tell the CEO that I could no longer recommend another greenhouse, and I still don’t.

But there are other reasons not to recommend greenhouse systems, including the way the roof drains rain and snow, the heat buildup and the problems with the state energy codes. The latest building codes seem set up to make it almost impossible to pass the heat-loss calculations we’re required to provide. Windows in the walls, on a vertical surface, are designed to drain very well, and the energy codes are more favorable to vertical glass for heat loss. Glass roofs are the problem.

You’re better off building a standardized wall and roof system and incorporating view windows where you want them for light, ventilation and fire exit, along with skylights from a reputable company that are warrantied against leakage. There are a few skylight companies that will, but I highly recommend not having low-profile skylights, installed close to the roof surface. Instead, have the skylights set at least 4 to 6 inches higher than the outside roof surface to allow for rain and snow to drain around the sealed curb.

As for how to heat the room, radiant floor heating is evenly distributed best, because the zone of where the heat is most useful is from the floor to the height of a person, throughout the room. Perimeter baseboards are also effective, but mostly by warming the area where the most coldness is radiating inward through the walls and windows. Forced air is least effective.

© 2018 Monte Leeper. Readers are encouraged to send questions to, with “Herald question” in the subject line, or to Herald Homes, 2 Endo Blvd., Garden City, NY 11530, Attn: Monte Leeper, architect.